The derivatives of long chain olefins having about 7 to 28 carbon atoms have considerable commercial importance in a variety of applications, including detergents, surfactants and freeze point depressants in lubricating oils. Primary derivatives which are used in many household laundry detergents include alcohols which are produced by hydroformylation, and alkyl benzenes, for example linear alkyl benzene (LAB) and modified alkylbenzenes (MAB) which are produced by the alkylation of benzene.
In the application to detergents, surfactants and the like, primary derivatives are generally converted to anionic or non-ionic detergents or surfactants by sulfonation or ethoxylation, respectively, of the derivative. Important considerations in providing effective detergents or general surfactants is cold water solubility/detergency, which is usually associated with hydrophobic branched olefin precursors, along with the need for good biodegradability which is usually associated with linear olefin precursors. Since these properties are conflicting it is not easily possible to provide surfactants, etc. meeting both requirements.
U.S. Pat. No. 5,849,960 (Shell Oil Company) discloses an alternative solution to this problem by providing a new composition of controlled branching alcohol, and their sulphate derivatives, via the olefin intermediate, in order to decrease hydrophobicity and thereby increase cold water detergency, whilst at the same time exhibiting good biodegradability.
The new compositions of U.S. Pat. No. 5,849,960 are prepared using a process for producing controlled branching primary alcohols from a linear olefin feed in two stages, via their branched olefins. The olefin feed is usually a distribution of at least 50 weight % of linear mono olefins in a specified carbon range, the remainder of the feed being olefin of other carbon number or carbon structure, diolefins, paraffins, aromatics and other impurities, depending on the origin or synthesis process used in providing the feed. The location of the double bond is not limited, the olefin feed composition may comprise alpha-olefins, internal olefins or a mixture thereof. The alkyl branched primary olefins obtained therefrom have from 7 to 35 carbon atoms, and an average number of branches per molecule chain of at least 0.7, containing not only methyl branches but also ethyl branches.
U.S. Pat. No. 6,187,981 (UOP) discloses preparation of modified alkyl benzenes (MAB) and their sulfonates (MABS) by paraffin isomerization and dehydrogenation to olefins, alkylation by olefins of aromatics, and sulfonation. The paraffinic feed for isomerization comprises linear or normal paraffins having a total of 8 to 28 carbon atoms per molecule, and the isomerised stream for dehydrogenation contains a higher concentration of lightly branched paraffins.